Add in existing flight pieces: flight/report/log

These pieces come from the old telemetrum firmware.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 160 insertions, 0 deletions

diff --git a/ao_flight.c b/ao_flight.c
new file mode 100644
index 00000000..f31b4cd4
--- /dev/null
+++ b/ao_flight.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright © 2009 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+
+/* Main flight thread. */
+
+__xdata struct ao_adc	ao_flight_data;
+__data enum flight_state	ao_flight_state;
+__data uint16_t			ao_flight_state_tick;
+__data int16_t			ao_flight_accel;
+__data int16_t			ao_flight_pres;
+__data int16_t			ao_ground_pres;
+__data int16_t			ao_ground_accel;
+__data int16_t			ao_min_pres;
+__data uint16_t			ao_launch_time;
+
+/* Accelerometer calibration
+ *
+ * We're sampling the accelerometer through a resistor divider which
+ * consists of 5k and 10k resistors. This multiplies the values by 2/3.
+ * That goes into the cc1111 A/D converter, which is running at 11 bits
+ * of precision with the bits in the MSB of the 16 bit value. Only positive
+ * values are used, so values should range from 0-32752 for 0-3.3V. The
+ * specs say we should see 40mV/g (uncalibrated), multiply by 2/3 for what
+ * the A/D converter sees (26.67 mV/g). We should see 32752/3300 counts/mV,
+ * for a final computation of:
+ *
+ * 26.67 mV/g * 32767/3300 counts/mV = 264.8 counts/g
+ *
+ * Zero g was measured at 16000 (we would expect 16384)
+ */
+
+#define ACCEL_G		265
+#define ACCEL_ZERO_G	16000
+#define ACCEL_NOSE_UP	(ACCEL_ZERO_G - ACCEL_G * 2 /3)
+#define ACCEL_BOOST	(ACCEL_NOSE_UP - ACCEL_G * 2)
+
+/*
+ * Barometer calibration
+ *
+ * We directly sample the barometer. The specs say:
+ *
+ * Pressure range: 15-115 kPa
+ * Voltage at 115kPa: 2.82
+ * Output scale: 27mV/kPa
+ * 
+ * If we want to detect launch with the barometer, we need
+ * a large enough bump to not be fooled by noise. At typical
+ * launch elevations (0-2000m), a 200Pa pressure change cooresponds
+ * to about a 20m elevation change. This is 5.4mV, or about 3LSB.
+ * As all of our calculations are done in 16 bits, we'll actually see a change
+ * of 16 times this though
+ *
+ * 27 mV/kPa * 32767 / 3300 counts/mV = 268.1 counts/kPa
+ */
+
+#define BARO_kPa	268
+#define BARO_LAUNCH	(BARO_kPa / 5)	/* .2kPa */
+#define BARO_APOGEE	(BARO_kPa / 10)	/* .1kPa */
+
+/* We also have a clock, which can be used to sanity check things in
+ * case of other failures
+ */
+
+#define BOOST_TICKS_MAX	AO_SEC_TO_TICKS(10)
+
+void
+ao_flight(void)
+{
+	__data static uint8_t	nsamples = 0;
+	
+	for (;;) {
+		ao_sleep(&ao_adc_ring);
+		ao_adc_get(&ao_flight_data);
+		ao_flight_accel -= ao_flight_accel >> 4;
+		ao_flight_accel += ao_flight_data.accel >> 4;
+		ao_flight_pres -= ao_flight_pres >> 4;
+		ao_flight_pres += ao_flight_data.pres >> 4;
+		
+		switch (ao_flight_state) {
+		case ao_flight_startup:
+			if (nsamples < 100) {
+				++nsamples;
+				continue;
+			}
+			ao_ground_accel = ao_flight_accel;
+			ao_ground_pres = ao_flight_pres;
+			ao_min_pres = ao_flight_pres;
+			if (ao_flight_accel < ACCEL_NOSE_UP) {
+				ao_flight_state = ao_flight_launchpad;
+				ao_flight_state_tick = ao_time();
+				ao_report_notify();
+			} else {
+				ao_flight_state = ao_flight_idle;
+				ao_flight_state_tick = ao_time();
+				ao_report_notify();
+			}
+			break;
+		case ao_flight_launchpad:
+			if (ao_flight_accel < ACCEL_BOOST || 
+			    ao_flight_pres + BARO_LAUNCH < ao_ground_pres)
+			{
+				ao_flight_state = ao_flight_boost;
+				ao_flight_state_tick = ao_time();
+				ao_log_start();
+				ao_report_notify();
+				break;
+			}
+			break;
+		case ao_flight_boost:
+			if (ao_flight_accel > ACCEL_ZERO_G ||
+			    (int16_t) (ao_flight_data.tick - ao_launch_time) > BOOST_TICKS_MAX)
+			{
+				ao_flight_state = ao_flight_coast;
+				ao_flight_state_tick = ao_time();
+				ao_report_notify();
+				break;
+			}
+			break;
+		case ao_flight_coast:
+			if (ao_flight_pres < ao_min_pres)
+				ao_min_pres = ao_flight_pres;
+			if (ao_flight_pres - BARO_APOGEE > ao_min_pres) {
+				ao_flight_state = ao_flight_apogee;
+				ao_flight_state_tick = ao_time();
+				ao_report_notify();
+			}
+			break;
+		case ao_flight_apogee:
+			break;
+		}
+	}
+}
+
+static __xdata struct ao_task	flight_task;
+
+void
+ao_flight_init(void)
+{
+	ao_flight_state = ao_flight_startup;
+
+	ao_add_task(&flight_task, ao_flight);
+}
+